I use 2-part epoxy. Usually Devcon 2-part, which I buy in tubes in the hardware store. But any type, usually. I usually buy epoxy with the longest working time possible. 30-minute epoxy, or better yet, 90-minute epoxy. The longer the working time the better the bond. (I avoid 5-minute epoxy like the plague.)

Working time of thinned epoxy would most likely depend on how thin. Presumably the more alcohol, the longer it takes to go off.

I’ve even used ordinary “rubbing” alcohol at 70%, but the stronger the concentration the better.